सीसरूपं सुवर्णपत्त्रेणावलिप्तमभ्यन्तरमष्टकेन बद्धं गाढपेटकः ॥ कZ_०२.१४.२७ ॥
sīsarūpaṃ suvarṇapattreṇāvaliptam abhyantaram aṣṭakena baddhaṃ gāḍhapeṭakaḥ
A ‘tight box’ is one in which a lead-like form is coated with gold leaf, and the interior is fastened with an octagonal (or eight-part) binding.
A dense base metal core (lead) is made to pass as gold by gold-leaf coating, then hidden within secure-looking packaging.
Do not treat sealed packaging as proof of purity; require material verification beyond outward appearance.